The NPAR1WAY Procedure

Overview: NPAR1WAY Procedure

The NPAR1WAY procedure performs nonparametric tests for location and scale differences across a one-way classification. PROC NPAR1WAY also provides a standard analysis of variance on the raw data and tests based on the empirical distribution function.

PROC NPAR1WAY performs tests for location and scale differences based on the following scores of a response variable: Wilcoxon, median, Van der Waerden (normal), Savage, Siegel-Tukey, Ansari-Bradley, Klotz, Mood, and Conover. Additionally, PROC NPAR1WAY provides tests that use the raw input data as scores. When the data are classified into two samples, tests are based on simple linear rank statistics. When the data are classified into more than two samples, tests are based on one-way ANOVA statistics. Both asymptotic and exact p-values are available for these tests. PROC NPAR1WAY also provides Hodges-Lehmann estimation, including exact confidence limits for the location shift.

PROC NPAR1WAY computes empirical distribution function (EDF) statistics, which test whether the distribution of a variable is the same across different groups. These include the Kolmogorov-Smirnov test, the Cramér–von Mises test, and, when the data are classified into only two samples, the Kuiper test. Exact p-values are available for the two-sample Kolmogorov-Smirnov test.

PROC NPAR1WAY uses the Output Delivery System (ODS), a SAS subsystem that provides capabilities for displaying and controlling the output from SAS procedures. ODS enables you to convert any of the output from PROC NPAR1WAY into a SAS data set. See the section ODS Table Names for more information.

PROC NPAR1WAY uses ODS Graphics to create graphs as part of its output. For general information about ODS Graphics, see Chapter 21: Statistical Graphics Using ODS. For specific information about the statistical graphics available with the NPAR1WAY procedure, see the PLOTS= option in the PROC NPAR1WAY statement and the section ODS Graphics.